Internal combustion engine



1 Dec. 8, ,1942. H. E. HOGAN 1 INTERNALJCOMBUSTION ENGINE Filed Feb. 1e, 1942 5 sheets-sheet 2- INVENTOR.

#ra/M,

ATTORNEYS.

l Dec. s, 1942.`

- l. 121,304,407 `i v AINTERML COMBU'STION ENGINE 'I v I Filed Feb. 16.: 1942 l s sheets-Shar sl e Wfy f Dcls, 1942.

INTERNAL COMBUSTION ENGINE Filed Feb. 16, 1942 H. E. HGAN 1 2,304,407

` INVENTOR. l www N m mf@ IATTORNEYS. j Y

Dec. s; 1942. l H. E. HQGAN 2,304,407 INTERNAL cMBUsTIoN ENGINE i 1,

` vFiled Feb. 16l 1942 S sneetsshen s @y 0 @i BY @KKK/www0? M il w//#M madness-1942" N, v Vj 2,304,407

*umsn'ls'rArss-f PATNT 'OFFICE' ti-charged two or four cycle horizontally op- Aengingand"comliustion orior supplying a triple parts `and whlch'is alsoulnternally-air cooled.` L 5- enging stroke. i Alltfurther f has i'or its Vobject a tour -cycle ln- The invention consists in the novel features c j ternal'combustion engine'in which the fuel is inand Yin the combinationsand constructions here- Y compressionlstroke.` andthe air forcedV into the `In describing this 'inventionfreference is had `cylinders duringthe suction s trokezthrough'` an4 loto the accompanying drawings in. which like Iintakevalvein theoutecyllnder headandalso "characters desi ate corresponding parts'ln all `throughavalve in thepistonhead from -a'transtheviews. `ccxnbustionchamber.withaironthe intake stroke ing ina direction axially otfthe crankshaft. i, o! the piston to `coinpletelyilll'the combustion 15 Figure Zisyiew similar toFljgure 1, parts `bechamber, andalsjlnbo'thelcylinders during the lngremoyed."` f i scavenging stroke Sto i'orce` the exhaust `gases Figure 3 is alon'gitudinal sectional viewthrough piston,` which air is `used 'during the scavengingl jacent cylinder head removed. i charge is4 released by theopening'ofithe exhaust seen inFigure 4.

stroke; with meansior supplying airunderi'pres- The invention jis `hereaillustrated fas em-bodied `stroke for combustion on thepower stroke, or a to certain features, it may beembodied in armo- `two cycle` engine which the fresh air used for i tor having one cylinder' or a bank of cylinders. i derv pressure.'

' It `further has for object mechanism i'orcar-A ycentral -blockor body 3, which isi'ormed'with'an y rying out themethod o! operating 'artour cycle `air pressure `chamber L 'I'hecylindersarehere finto the air inthe cylinder `during. thefcomprespart cylindrical skirtfportion 8 extending through savenging strokes through the piston ihead, or` o1'` .4i

from, a transfer chamberprefer`ablyl through `a Ian arcuate or` semi-circular` insert Il or l2 in valve-in thepistonl andimectingfun intbhe so theinnerfend Of'the cylinder `I 0r 2, theY Inner combustioncharnber duringthe"v scavenging and;4 I #face of thelinsertbeing concentric with the axis "compression stroke; V f A` `twocycle engine (Figure 6) withtwo intake and suitably interlocked against endwise movement,

`2,304,407 A mrmanoonmusnos nimma,Y y i `nuuglsnlnpmi.owen, N. Y. L y applicants Febr-nag, 1a, 1942, semina. 431,080

n Y, l comuniones-41)" H -v Thisinvention has for"` its generalfobjecta mul-` 'a multi#chargeV of air Iunder pressure 4'for' scavposed, internal combustion engine, `which isparcharge ofair for a four cycleengine on the sucticularly compact or `dat in arrangement :of its` tion strokeand amulti-charge'oi' air on the scav- Jected-into the air in the cylinder'during the inafter'set i'orthand claimed.

terchamber, or means for multi-chilirging the Figure lis a side elevation otthis'enginellook-` 1 l i'romthe cylinders and cool the cylinders the cylinders.` e i internally. .y i H y `Figurei is an enlarged end view of one side of 4 It further has for its object a two cycle fengine 20 the central body showing the adjacenticylinder in whichthe air used is compressedliy` the pis" head and the insert therein, ln which the head nlinra transfer chamber in the cylinder inthe is partly mounted, this beingtaken approximately rear ot the pistonfduringthe power stroke'of the on line 4 4;r Figure 3, with the 1valve in the adstroke, whenl the pressure` otfthe combusted a Figure 5 is "affragm'entary 'elevation o1' parts valve and :which air -used during the 'scavenging i Figure 6 is a view similar to Figure 3 of a slightstroke `is mixed withv fuel on the compression ly moditledform. .i t

`sure to thecombustion` chamber-for scavenging 30 inv an engine having two `banks-of cylinders as a and for mixing with fuel on the compression horizontally opposed motor, althoughln regard combustion'enters th combustion chamber un l and ldesignate apair` of horizontally opf i 35 .posed cylinders mountedon. opposite sides of` a i internal combustionwengine` comprising blowing shown as `formed withfjackets 5 i'or receiving an air under i pressure into thec'ombustion chamber external liquid cooling rnediumfas` water. y during thesuctionstroke and: also during'y the 40 6 land?! are piston heads workingdn the cyli'n-A scavenging stroke, and" injecting amotive iiuid i ders I and 2,`these being connectedtogetherby a sionlstroke, the airbeing `preferablyvpassed into the body 3, this skirt sliding on `the cylinder walls. the combustion chamber during the suctionand The skirt 8 is substantially semi-circular in crosssection and slidablyfits the cylinder walls."V 9 and operating a.two cycle engine,withlexhaustvalves I0 are stationary heads at theinner ends of the in the outer cylinder headand means for `blowing cylinders I and 2, these slidably iitting the inner air under pressure into `thel combustion chamber face of theiskirt portion 8 and the inner face of Y `of`fthe cylinderandAv ofthe same radius` as theiiri-l It further has for its'objecta multi-charged 'or ner 4face of the skirt 8; Theinsert Il or vI2 is' compression chambers, with means for supplying 55 it being shown asfformed witn` peripheral, semivthe body s.

annular, arcuateflange I3 interposedbetween remote from the body 3 as the outerv ends. This explanation is made because in considering the f strokes of an internal combustion engine, the

in stroke of the piston is that awayfrom the crank shaft as the compression stroke and out stroke that toward the crank shaft as the power stroke.

'Each insert II or I2 is formed in two sections, each being substantially quarter circular, the sections lapping eachother at 9ll,and these sections are pressed outwardlyin order to snugly flt'the cylinder walls by spring 9I,and hence seal the joint between the edges of the semi-4 circular skirt 8 andthe cylinder wall.

Passages are provided connecting portions of the cylinder I or 2 on opposite sides of the piston heads 6 or 1 and alsopassages are provided openshaft, which is actuated from the crank shaft of the engine in any suitable manner. V22 designates the valves; 23 the rocker arm mechanism coacting with the cam shaft 24. 25 are ports controlled by the valves 22, these communicating with suitable manifolds 26.

21 designates a fuel injector for each cylinder, this operating to inject fuel intothe compression chamber ofthe cylinder during the compression` stroke. It is actuated and timed in any well known manner from the crank shaft, and invso far as this invention is concerned, it is merely a fuel injector. Therefore, furtherv description thereof is thought to be unnecessary.

28 designates the crank shaft, the crank pin 29 of which is connected to theskirt portion 8 of the piston by means including a connecting rod 30 lugs 35 on the outer side of the skirt portion 8,

ing intothe inner ends Vof the cylinders on the rear side of the pistons. The portions of the cylinders on Athe rear air transfer chambers. loaded valves are provided in-these passages, the valve in the passage leading from the transfer chamber to the combustion chamber being opened at the'end of theintake'stroke -of the side of the pistons constitute pressure of the. air in the transfer Vchamber on the valve. The valve in the piston is also opened during the scavenging stroke by the pressure of g the air inthe transfer chamber, while the pressure inthe combustion chamber is being released by reason of the fact thatthe exhaust valves are open. The valves controlling the intake passages for the transfer chambers are also spring-loaded and normally-closed, andare held closed by the -compression in the transfer chamber during the power strokes and are opened during the scavengingstrokes by vacuum in the .transfer chamber and. airgpressure in the body 3. In the illustrated embodiment of the invention, these passages andthe valves are located respectively .in

Normally-closed, spring- Y pistonj in the combustion chamber yby the higher the piston heads 6, 1 and cylinder heads 9, l0.

Each'of the piston heads 6, 1 is provided with a valve passage therethroughin which is located a normally-closed, spring-pressed or loaded valve I5 or I6 `pressed toward closed position by a spring, ask IB, these valves opening toward the outer ends of the cylinders, or outwardly from thepressurefaces'of the pistons. Each of the heads 9, IIl'is provided with asimilar valve I9 or 20 which also isk normally closed and spring loaded, and opens toward the outer ends'of the cylinders ortoward the piston heads 6, 1l of the cylinders respectively. Eachof the valves I5, I6, I9 or v20 is. tubular With'radially extending passages, as 2|, under the heads of the valves. The cylinders are provided with valves, preferably located in the outer cylinder heads and mechanism for operating the valves. These valves may both be exhaust valves, or in some constructions, one

may be an exhaust valve and the other an intake valve. The valves are alike in constructiomand preferably are exhaust valves. They are operated against the action of returning springs by `pairof cylinders I,

and a cross-head or slide, the rod being pivoted at its outer end at 3| to the slide or cross-head 32. The slide or cross-head 32 is connected to the skirt portion 8 through a slot 33 in the p0rtion of the cylinder walls and in the body 3 'coveredby theskirt portion 8. As here shown, the

cross-head is formedv vwitha shoulder or lug 34 interflttingV in .a groove or between two spaced these lugs 34, 35 Working in the slot 33. The

`crank shaft 28 is located at one side ofthe cylin-` ders and extends in adirection crosswise of the axis o'f the cylinders. It is mounted in a suitable base 36 on which the body 3 andthe cylinders are also mounted. n

` Air under pressure is supplied to the air chamber 4 in the body 3 bysuitable means, here shown as a blower 31, the casing of which is mounted on the bodyv 3 and which has an air intake 38. The` .diary gear 43 meshing therewith, and with a gear 44 on the propeller shaft. The cam shafts 24 are actuated from the crank shaft, one through thel gear -43 meshing with the gear 45 ron one of the cam shafts, and the other cam shaft through gear 46 meshing with the gear 44 on the output o r propeller shaft, and a gear 41 on said other cam shaft. The cam shafts 24 and the gears 43 and 46 are mounted on a suitable support or housing 48 carried by the base 36. The blower shaft 40 is actuated from the crank shaft 28 through a gear 49 on the output or propeller shaft 4I and meshing with a pinion 50 on the blower shaft 50. The crank shaft 28 andthe output or propeller shaft 4I are suitably mounted in the base 36 and housing 48.

52- designates'spark plugs connected in suitable necting rod 300 to the crank of thexcrank shaftk 290 in the usual manner, the piston heads 6Il0and 100 corresponding to theV piston heads 6, lrbeing Vconnected together substantially as shown in Figure 3, but lchel piston head100 merely acts as a compressor and is not a power piston. This rocker arm mechanism coacting with a cam form of engine as shown is of the conventional The air chamber 400 has" an intake valve 4IlI.

head son,

rearfof the piston 80|! d 2,304,407. d type or not a horizontally opposed engine; 'I'he piston head 600 is provided'with the valvecontrolled passage therethrough; as in Figure 3. i controlled lby d d This `chamber 400 also communicates through a valve-controlled passagejinthe-cylinder d with Vthe transfer chamber l540;'a`s in Flgure, in the rear of the pistonhead 600, and

the `pi'storrfllllionfits inwardl stroke toward the e body compresses the air. The compressed air passes through the valve-controlled passage ofthe Y cylinder head 800 intofthe chamber540 in the during the outward stroke der, even when the throttle is open only partly.

Also, the engine'shown in Figure 3 may be operated as a four cycle engine by timing and operating one of Vthe valves 22 as an 'air intakeb valve suitably modifying-the cam shaft 24 and i utilizing one of the manifolds 26, as an airlntake of the piston 600'. The air chamber 400 com municates with the cylinder` 2M inwhich'the piston 'IIIII Works inthe rear ofthe piston 100, so that the pistonllll` acts as Aan' air compressor piston` during its vinward strokeand does not act as a power piston., The transfer chamber 540 to i which the blower is connected has an intake valve manifold. Inthis operation as a four cycleV engine, the valve l22 acting as an intake valve will be opened while the piston is onits suction stroke; At the. inn'erstroke of the piston. 6, the airinthe transfer chamber- 54 behind thepiston will pass through the passage controlled by the valve I5 in the combustionichamber in the head 6. Assumingfthat the piston 6 is on its suction stroke, the valve `22acting as an air intake valve will be n open. As the piston travels in on the suction 402 Ythrough which air enters the transfer chamber, B40, as the'piston 800 is o n the outer stroke. At the end of the outer stroke, valve 402 closes and the air is compressed in chamber Il and is forced through valve passages in cylinder head into transfer. chamber 540. `As thepiston travels in on the inner stroke, the air Vin transfer chamber 540 is compressed and forces the valve i in piston lllopenand the air under compression is `forced into the combustion chamber through the valve passage in piston 800 forcing Vburned `gases out the mechanically operatedfexhaust valves in the outer cylinder heads; The valve chamber is retained, compressed "and mixedwith fuel from the injector 21for.combustion on'the powerstroke. `'Iheiiiow of air into the air chamber 400 is con,-

troued by the valve m wmenmay be suction f operated `ortimed and operated in any conventional manner. Briefly, first airis received in the chamber 40|! and in theispace between the piston head 100 and the cylinder head 900. this air being compressed and forced past thevalve in the piston head 900 into the transfer chamber 540 which is full of uncompressed air blown intothe valve passage 402 in the transfer chamber 540.as the piston "000 is on the scavengingand compression stroke Thus, the transfer` chamber 540 receives a multi-charge during the scavenging. and compression stroke of the piston 6M! and this double stroke, air is` drawn or blown into the combus'-,

tion chamber until thepiston isnear theend of the suction stroke, the intake.y valve 22 closes at the end of the suction" stroke'or inner stroke of thepiston 6.x The valve I-` inthe piston headl 6 i vwill be` opened bythe lowerpressure in the combustion chamber of the cylinder I and the `airA compressed in the rea-r of the piston 6, inthe transfer chamber `54; will pass through the open valve `I5 into Vthe v combustion chamber ofthe cylinder I. This operation forcesa multi-charge of air into the combustion chamber. When the piston 6 is on its compressionstroke, the valve 22 acting as anjlntake valvewi1l be `closedby its timing and operating mechanism, and the V valve I5 will be closed by the compression and springloaded valve; The valve I9 will be opened by the air pressure `within the chamber 4 of the `body 3 l and the vacuum created in the chamber 54', so that air flows into the transferchamber 54`behind the `ypiston 6. During the compression stroke, the fuelis injected. as before. by the fuel injector into the air in the combustion chamber. During the power strokefthe air is compressed in the transfer' chamber 54.l At the' end ofthe power stroke, the other valve 22 acting as an exhaust valveisopened and the pressure of the air in the-transfercha'mber 54`forces open the valve I5,` permitting air to pass into the lcombustion chamber during the scavengingrstroke. While `these actionsV are taking place. similar actions are taking place in the cylinder 2 in the same order but 4at different periods` of timing.V

In operating this engine, as a two cycle engine,

i both valves V22 are operated and timed as exhaust charge is forced through thehvalve passage in the piston 600 into the combustion chamber to force the burned gases out ofthe cylinder, at the end of the power strokeof the' piston BIIII and admitting the charge to be compressed and fired on the out stroke `of the piston 800 which chargellls theV cylinder in which the piston 000 works.

d In any form of the invention, this completely iillingf` of the power cylinder lwith air to support combustion maintains a substantially uniform compression, regardless of the throttle position of the engine, as the cylinder is always full of'somevalves. During the powerstroke, obviously both valves Iii` and I8 willbe vclosed and the air pre- 'vinusly taken in behind the piston 6 will be compressed in the ltransfer chamber, At the end of thepower stroke,` the exhaust valves V22 will `be opened and the air from the transfer chamber 54 passed into the combustion chamber Vof the cylinder through the open valve I5, facilitating the scavenging andsupplying the air to support combustion of the fuel, which is injected from the fuel injector 21 during the scavenging and compresson stroke. While'the air is thus passing into the combustion chamber through the open valve I5, the pressure in the chamber 4 andthe vacuum in chamber 54 opens the valve I9 permitting the transfer chamber to be filled with air. Duringv the power strckebthe air in vthe 'chamber 54 is compressed rto be discharged into the combustion chamber during the scavenging and compression stroke. The piston 1 in the lcylinder 2 is going through a similar cycle, but

while the piston 6 is on its scavenging and Vcomthing, and there is no excess vacuum. in the cyun# vto compress a chargefof ber A the wing of an airplane.

` stroke,

pression stroke, the piston 1 is on its power stroke.

In the engine shownin Figure 6, the operation is thesame as in a four cycle or two cycle engine before described, except that the piston vlllacts as an yadditional intake controlled passage I9 into the compression chamf 540 of the cylinder l, multiplying the charge of air in the transfer chamber 5,40 to be compressedland forced into the combustion chamber andtransfer chamber) air through the valveowing to its construction, is

`combustion chambers during of the pistons and under the higher pressure in during the compression cylinders` resulting in an en t.

gine with less weight, less` parts, less space re-x quired` and with less weight per horsepower than in conventional engines, due to the largervoluxneof high `compressed gases Yin the combustionchamber. Such an engineiwould be especially adaptable to high altitude flying. In the multicharged two cycle engine, due to the volume of air that enters* the -combustion chamber, this engine should be adaptablev for Diesel engine" operation.

What I claim is:

1. In an internal combustion engine, opposing cylinders arranged in axial alinement, pistons in` cluding heads working in the cylinders respecportion contively, and a part-cylindrical skirt necting the heads, opposite outer ends'of each cylinder constituting firing chambers, a reciproeating cross-head the cylinders and extending across the body and a crank shaft, a

slidable on the outer sides of connected to the skirt portion, connecting rod between the cross-head andthe crank shaft, and int ke and exhaust valves'operable to control the flow of air and fuelto and ends of the cylinders, the

working inthe cylinders respectively, and a part.-

cylindrical skirt portion connecting the heads,

the body being formed with an rair chamber,

heads at the inner ends of the cylinders adjacent the body and coacting with the cylinder walls and thel adjacent portion of the connecting skirt portion, thereby forming an' air transfer chamberbelind the piston .heads at the inner l piston and cylinder heads having valve passages therethrough, the latter opening in the body,

heads and said cylinder. heads, means for sup plying air under pressure 'to the chamber of the body, thevalves in the cylinder headsbeing arranged to open under the lower pressure in the the intake strokes the transfer chamber and the valves in said cylinder heads arranged to open the transfer chamber and towardy the piston heads during the com-` pression strokes of the pistons and to close dur ing thev power and intake strokes, a fuel injector for' eachfcylinder, a crank shaft, a connecting rod,andv means for connecting the rod'to the skirt portion to translate the reciprocating movement of the pistons to the crank shaft.

4. In an internal combustion engine, a body formed with the body, a piston including a head working'in the cylinder, and. a part-cylindrical skirt portion extending through the body, a crankshaft located laterallyatone side of the cylinder and extending in a direction crosswise oi the axis of the cylinder, aV connecting rod, means connect ing the connecting rod to the skirt portion ofthe piston, a head at the inner end of the cylinder adjacent the body providing an air transfer pas-` sage, valve passages in the piston head and said cylinder head, `the latter passage opening intoY the body chamber, normally-closed, springloaded valvesjnsaid passages for controlling theA fiow'of air from the chamber of the bodyinto the transfer chamber and from the transfer chamber into the compression and combustionchamvber of the cylinder, the valves'opening toward the from the combustion chambers of the cylinders.

l2. In an internal combustion engine, a body, cylinders arranged in axial alinement on opposite sides of the body, pistons including heads working in the cylinders respec'tively,` and a part-cylindrical skirt portion vconnecting the heads, the body having a guide opening through which the skirt portion works, opposite outer ends of the cylinders constituting flring chambers, stationary heads at the inner ends of the cylinders adjacent 1 the body and coacting with the skirt portion to hold compression, a reciprocating cross-head slidable on the outer sides of the cylinders and extending across the body and connected skirt portion, a crank shaft, a connecting rod between the cross-head and the crank shaft, intake and exhaust valves operable tocontrol the flow of air and fuel lto the exhaus'tgfrom the cornbustion chambers of the cylinders, the intake valves including normally-closed', spring-loaded valves inthe piston heads openable by air pres- Vsure in the cylinders in the rear of the pistons during the suction stroke, and means `for supplying and controlling the flow of air under pressure to the' cylinders in the rear of the piston heads.

3. In a four-cycle, internal combustion engine, a body, cylinders arranged in axial alinement on opposite sides of the body, pistons includingheads tothe outer end of the cylinder remote from the body, exhaust and intake valves at such outer end, meansfor operating the. exhaust and intake.

valves, and means for supplying Vair under pres sure to the chamber' in the body.

y 5. In an internal combustion engine, a body formed with a chamber, a cylinder mounted on the body,r a piston including a head Working .in the cylinder, and a part-cylindrical skirt portion extending through the body, a crank shaft located laterally at one side of the cylinder and extending in adirection crosswise of the axis of the cylinder, a connecting rod, means connecting the connecting rod to the skirt portionv of the piston, a head at the inner end of the cylinder adjacent the body providing an air transfer pasz sage, valve passages in the piston head and said cylinder head, the latter passage opening into the body chamber, normally-closed, spring-loaded valves iny said passages for controlling the flow of air from the chamber of the body into the transfer chamber and from the transfer chamber into the compression and combustion chamber of the cylinder, the valves opening toward the outer end of the cylinder remote from the body, exhaust andv intake valves at such outer end, means for operating the exhaust and intake valves, means for supplying air under pressure to the chamber in the body, and means for innormally-closed, Y spring-loadedvalves in the pasages of the piston a chamber, a cylinder mounted on' the compression stroke of the piston. Y

6. In an internal combustion engine, a body formed with a chamber therein, cylinders mounted on opposite sides of the body in axial alinement, pistons including heads working in the cylinders respectively, and a' part-cylindrical l skirt portion connecting the piston heads and with the inner face of the skirt portion, the piston heads and saidcyllnderheads having valve Y passages therethrough, normally-closed, spring- A `loaded valves in said passages and opening toward the ends of the cylinders remote from the outer ends of the cylinders remote from the body,

'and operating mechanism therefor, fuel injectors I located to inject fuel into the combustion chambers of the cylinders during the compression strokes of the pistons, a crank shaft located at y body, means for supplying air under pressure to` said chamber, exhaust and intake valves at the one side of `the cylinders and extending in a direction crosswise of the axis of the cylinders.

and motion transmitting means between the` crank shafty and the skirt portion including `a connecting rod.

'1. In an internal combustion engine, a body, l l cylinders arranged in axial alinementon opposite sides of the body, pistons including heads `working in the cylinders respectively, and a partcylindrical skirt portion connecting the heads,

\ the body having a guide opening through which the skirt portion works, opposite outer ends of the cylinders constituting firing chambers, station-` ary headsl at the inner ends of the cylinders adjacent the` body and coacting with the skirt por- 4 tion`to hold compressioma skirt portion arcuate in cross-section connecting the last heads and `nested in the skirtvportion connecting the piston heads, a reciprocating cross-head slidable on the outer sides of the cylinders and extending across the body and connected to the skirt portion, a crank shaft, a connecting rod between the crosshead andthe crank shaft, intake and Yexhaust valves operable to control the :dow of air and fuel to the exhaust from the combustion chambers of the cylinders. the intake valves including normally-closed, spring-loaded valves in the pis- 4ton heads openable by air pressure behind the piston heads on the suction stroke, andmeans for supplying and controlling the flow of air under pressure to the cylinder in the rear of the piston heads.

8. In an internal combustion engine, opposing cylinders arranged in axial alinement, pistons including heads working'in the cylinders respectively, and a part-cylindrical skirt portion connecting the heads, the outer end of one cylinder constituting the combustion chamber, a cylinder head at the inner end of said cylinder, the` piston head and the cylinder head having spring-loaded lvalves therein, an air inlet between the cylinder head with the valve therein and the other piston head, whereby the latter `piston head acts to compress the air between it and said cylinder head,

and means for supplying fuel to the combustion chamber, a crank shaft and a connecting rod` between it and said other piston head.

9. In an internal combustion engine, opposing cylinders arranged in axial alinement, pistons including heads working in the cylinders respectively, and a part-cylindrical skirt portion connecting the heads, one cylinder and piston being an ignitable fuel compression and power cylinder and piston, and the other `cylinder and piston being an air compression cylinder `ancl piston,

, `the outer end of the power cylinder constituting the combustion chamber, a cylinder head 4at the inner end of said powercylinder, a. crank shaft, and a connecting rod between it and the air compresser piston, the space between the power piston head and the power cylinder head constituting an air transfer chamber, and the space` between said cylinder headand the compressor HUGH E. 

